JP7220877B2 - electric field communication system - Google Patents

Description

The present disclosure relates to systems that communicate using changes in electric fields.

In recent years, when working with various work equipment such as power shovels, the state of detachable parts attached to the tip of the arm is monitored via a communication network, and the operating status of this work equipment is appropriately monitored. required to manage.

When collecting signals from sensors via a wireless network, the signals from the sensors can be received even if the parts, etc. to which the sensors are attached are separated from the monitoring device on the main body that monitors the status of these parts, etc. , the attachment and detachment of parts cannot be detected. Also, if multiple work devices operate within range of the wireless network, the monitor collects signals from all sensors associated with the work devices within this range. As a result, the signal from the sensor attached to the part attached to the tip of the arm, which is the other party to communicate with, and the signal from the sensor attached to the other part cannot be reliably distinguished from the signal magnitude itself. .

Also, when signals from sensors are collected via a wired network, it is possible to reliably detect attachment and detachment of parts. However, it is necessary to provide a cable for communicating the signal from the sensor and a connector for connecting the cable to parts and the like. These cables and connectors are easily damaged during operation of the working device, and if the cables and connectors are damaged, signals from the sensors cannot be collected.

The present disclosure has been made in view of the above points, and one of its purposes is to provide a system and method for performing electric field communication using an electric field induced in metal or the like that constitutes a working device. It is in.

The present technology has been made in view of the problems described above, and one aspect of the present disclosure is an electric field communication system that performs communication using an electric field, comprising: a communication medium configured of a substance capable of transmitting an electric field; An electric field is generated according to a potential difference between a first electrode arranged on a communication medium side and connected to the communication medium via a coupling capacitance and a second electrode connected to the earth ground via a coupling capacitance. A first transmitter, wherein the first electrode is connected to a signal side of the transmitter and the second electrode is connected to a ground side of the transmitter; and a first receiver is arranged in contact with the communication medium. , wherein the first transmitter and the first receiver perform electric field communication via the communication medium.

1 is a schematic diagram of an electric field communication system according to an embodiment of the present disclosure; FIG. 1 is an overall configuration diagram of an electric field communication system according to an embodiment of the present disclosure; FIG. 1 is an overall configuration diagram of an electric field communication system according to an embodiment of the present disclosure; FIG. 1 is a schematic diagram of an electric field communication system according to a first embodiment of the present disclosure; FIG. 1 is a diagram illustrating a configuration example of an electric field communication system according to a first embodiment of the present disclosure; FIG. 4 illustrates the time variation of the voltage at the transmitter signal electrode in the electric field communication system shown in FIG. 3; Figure 4 illustrates the time variation of the voltage at the receiver ground electrode and the voltage of the battery ground with respect to earth ground in the electric field communication system shown in Figure 3; 4 illustrates the time variation of the voltage at the receiver signal electrodes in the electric field communication system shown in FIG. 3; 4 illustrates time variations of the voltage at the receiver ground electrode and the voltage at the receiver signal electrode in the electric field communication system shown in FIG. 3; 4 illustrates the temporal change of the voltage input to the receiving circuit in the electric field communication system shown in FIG. 3; FIG. 4 is a schematic diagram of an electric field communication system according to a second embodiment of the present disclosure; FIG. 10 is a diagram illustrating a configuration example of an electric field communication system according to a second embodiment of the present disclosure; 7 illustrates the time variation of the voltage at the transmitter signal electrode in the electric field communication system shown in FIG. 6; 7 illustrates the voltage over time variation in the voltage of the battery ground relative to the receiver ground electrode and earth ground in the electric field communication system shown in FIG. 7 illustrates the time variation of the voltage at the receiver signal electrodes in the electric field communication system shown in FIG. 6; 7 illustrates the time variation of the voltage at the receiver ground electrode and the voltage at the receiver signal electrode in the electric field communication system shown in FIG. 6; FIG. 7 illustrates temporal changes in voltage input to a receiving circuit in the electric field communication system shown in FIG. 6 ; FIG. It is an example of an equivalent circuit of the electric field communication system shown in FIG. 1 schematically illustrates an experimental setup in one embodiment of the present disclosure; FIG. Fig. 2 schematically illustrates an experimental setup (receiver signal electrode on the communication medium side) in an embodiment of the present disclosure; Fig. 2 schematically illustrates an experimental setup (receiver ground electrode on the communication medium side) in an embodiment of the present disclosure; 1 schematically illustrates an experimental setup in one embodiment of the present disclosure; FIG. Fig. 2 schematically illustrates an experimental setup (receiver signal electrode on the communication medium side) in an embodiment of the present disclosure; FIG. 11 schematically illustrates an experimental setup in an embodiment of the present disclosure (receiver signal electrode placed on the communication medium side, receiver ground electrode in communication with the communication medium); FIG. 11 schematically illustrates an experimental setup (receiver ground electrode placed on the communication medium side and in communication with the communication medium) in an embodiment of the present disclosure; FIG. 12B illustrates waveforms of signals obtained as a result of simulation in the configuration of FIG. 12A. FIG. 12B illustrates waveforms of signals obtained as a result of simulation in the configuration of FIG. 12B. FIG. 12C illustrates waveforms of signals obtained as a result of simulation in the configuration of FIG. 12C. FIG. 5 is a schematic diagram of an electric field communication system according to a third embodiment of the present disclosure; FIG. 4 is a diagram schematically showing an experimental setup in one embodiment of the present disclosure (both the receiver and transmitter are placed on the communication medium); 1 schematically illustrates an experimental setup in one embodiment of the present disclosure (transmitter above communication medium and receiver between communication medium and earth ground); FIG. 1 schematically illustrates an experimental set-up in an embodiment of the present disclosure (transmitter placed between communication medium and earth ground, receiver above communication medium); FIG. FIG. 12 schematically illustrates an experimental set-up in a positional embodiment of the present disclosure (both transmitter and receiver placed between communication medium and earth ground). 1 is a schematic diagram of an electric field communication system according to an embodiment of the present disclosure; FIG.

[Description of Embodiments of the Present Disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described. One embodiment of the present disclosure has the following configuration.

(Item 1) According to item 1, an electric field communication system that performs communication using an electric field,
a communication medium composed of a substance capable of transmitting an electric field;
An electric field is generated according to the potential difference between a first electrode arranged on the communication medium side and connected to the communication medium via a coupling capacitance and a second electrode connected to the earth ground via a coupling capacitance. a transmitter, wherein the first electrode is connected to the signal side of the transmitter and the second electrode is connected to the ground side of the transmitter;
a first receiver positioned in contact with the communication medium;
wherein the first transmitter and the first receiver perform electric field communication via the communication medium.

(Item 2) According to Item 2, the electric field communication system according to Item 1,
The communication medium is
a component in contact with the first transmitter;
a body in contact with the first receiver;
and the electric field communication system further comprises:
An electric field communication system, comprising a processing unit that detects that the component is detached from the main body when the magnitude of a signal generated based on the electric field transmitted from the first transmitter is less than a threshold. is provided.

(Item 3) According to item 3, in the electric field communication system according to item 2, the first receiver includes:
a third electrode connected to the earth ground via a coupling capacitance;
a fourth electrode disposed on the communication medium side;
a receiving circuit, wherein the third electrode is connected to a signal side of the receiving circuit, and the fourth electrode is connected to a ground side of the receiving circuit; the receiving circuit is connected to the transmitter; An electric field communication system is provided for outputting a signal corresponding to the potential difference between the third electrode and the fourth electrode caused by the electric field transmitted from.

(Item 4) According to Item 4, in the electric field communication system according to Item 2, the first receiver is disposed in contact between the earth ground and the communication medium, 1 receiver
a third electrode disposed on the communication medium side and connected to the communication medium via capacitive coupling;
and a fourth electrode arranged on the earth ground side and connected to the earth ground via capacitive coupling.

(Item 5) According to Item 5, in the electric field communication system according to Item 2 or Item 4, the first transmitter is disposed in contact between an earth ground and the communication medium,
An electric field communication system is provided, wherein the second electrode of the first transmitter is positioned on the earth ground side.

(Item 6) According to Item 6, the electric field communication system according to any one of Items 3 to 5, further comprising: Or comprising a sensor that detects the surrounding environment of the part,
An electric field communication system is provided wherein the first transmitter outputs a signal corresponding to the output signal from the sensor as a time-varying voltage across the first and second electrodes.

(Item 7) According to Item 7, the electric field communication system according to Item 6,
The sensor is a sensor that detects movement of the component,
An electric field communication system is provided in which the processing unit further calculates the operating time of the component based on the movement of the component detected by the sensor.

(Item 8) According to Item 8, the electric field communication system according to Item 6,
The sensor is a sensor that detects the surrounding environment of the first portion,
An electric field communication system is provided in which the processing unit further detects whether the component is placed in an appropriate operating environment based on the surrounding environment of the component detected by the sensor.

[Details of the embodiment of the present disclosure]
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or similar elements are denoted by the same or similar reference numerals, and duplicate descriptions of the same or similar elements may be omitted in the description of each embodiment. Also, the features shown in each embodiment can be applied to other embodiments as long as they are not mutually contradictory. However, embodiments of the present disclosure are not necessarily limited to such aspects. It will be apparent to those skilled in the art that the embodiments of the present disclosure can take many different forms within the scope defined in the claims.

FIG. 1A is an overall configuration diagram of an electric field communication system 100A according to an embodiment of the present disclosure. The electric field communication system 100A includes a main body 136 and parts 132 (attachment 132(1) and crawler belt 132(2) in FIG. 1A; hereinafter collectively referred to as parts 132) that can be attached to and detached from the main body 136. It is a system that can be applied to various working devices such as power shovels and robot arms. The electric field communication system 100A is mainly composed of a component side device 110 (110(1) and 110(2) in FIG. 1A), a main body side device 120, and a communication medium 130 for transmitting an electric field. The electric field communication system 100A performs communication between the component-side device 110 provided on the component 132 and the main body-side device 120 provided on the main body 136 through the electric field ef induced in the communication medium 130 . The structure of the electric field communication system 100A according to the present disclosure will be outlined below with reference to FIG. 1A, taking as an example the case where the electric field communication system 100A is applied to a power shovel. The power shovel illustrated in FIG. 1A is mainly composed of a detachable attachment 132(1) which is a part 132, a cabin which is a body 136 in which an operator rides, and an arm 134(1) which is a connecting portion 134. .

The component 132 includes a portion with which the component-side device 110 that communicates with the main body-side device 120 is in physical contact. For the component 132, for example, the environment around the component (such as humidity and temperature) and the state of the component itself (temperature, acceleration, on/off, etc.) need to be detected. In the power shovel, the parts 132 include an attachment 132 (1) attached to the tip of the working device, a crawler belt 132 (2) of the power shovel which is a device to be controlled by the main body 136, various filters such as an engine filter and an oil filter. Contains filters. The part 132 is configured to be detachable from the main body 136 via the connecting portion 134 . The parts 132 may be periodic replacement parts or consumables. In the present disclosure, two elements “physically contact” means that they are in contact to the extent that an electric field can be transmitted between the two elements. may exist. As an example, there may be a housing wall made of plastic or the like of the component-side device 110 that is a dielectric between the attachment, which is the part 132 of the power shovel, and the component-side device 110 .

Connecting portion 134 (arm 134 ( 1 ) and base portion 134 ( 2 ) in FIG. 1A; hereinafter collectively referred to as connecting portion 134 ) is a member connected between component 132 and main body 136 . , one in physical contact with part 132 and the other in physical contact with body 136 . The connecting portion 134 may be, for example, an excavator arm 134(1) if the component 132 is an excavator attachment 132(1), or an excavator base if the component 132 is an excavator track 132(2). Part 134(2). As described above, the part 132 and the connection part 134 only need to be in physical contact. A lubricant may be present.

The main body 136 includes a portion with which the main body device 120 that communicates with the component device 110 is in physical contact. The main body 136 is, for example, a cabin in which a worker who operates a power shovel rides.

The communication medium 130 includes a component 132, a connecting portion 134 that connects the component 132 and a main body 136, and a portion of the main body 136 that is made of a substance through which an electric field is transmitted, such as a conductor or a dielectric. As an example, the communication medium 130 is composed of a conductor represented by metal (for example, iron, aluminum, copper, etc.). For example, the main body 136 of the power shovel is composed of the frame of the power shovel, the window, the operator's seat, and the like. Each part of the communication medium 130 (the part 132, the connecting part 134, the main body 136) may be composed of materials capable of transmitting different types of electric field, or may be composed of materials capable of transmitting the same type of electric field. . Also, the component 132, the connecting portion 134, and the body 136 shown in FIG. 1A can each be composed of one or more elements. According to the present disclosure, the component-side device 110 and the component 132, the component 132 and the connection section 134, the connection section 134 and the main body 136, and the main body 136 and the main body-side device 120 physically contact with each other for electric field communication. A network is built. Therefore, communication is not established between the main body device 120 and the component device 110 if the respective parts are not in physical contact with each other. Therefore, even if a plurality of working devices or the like are operating within a narrow range, they will not communicate with a partner with whom they are not in physical contact. It should be noted that the component 132, the connecting portion 134, and the main body 136 that constitute the communication medium 130 can have various shapes.

The electric field communication system 100 further includes sensors 140 (two sensors 140 (1) , 140 ( 2 )), a processing unit 150 and an external communication device 160 . These are described in detail with reference to FIG. 1B.

In addition, as shown in FIG. 1A, for one main body 136, a plurality of parts 132 (attachment 132(1) and crawler belt 132(2) in FIG. 1A), a plurality of part-side devices 110 (two in FIG. 1A) Component-side devices 110(1), 110(2)) and a plurality of sensors 140 (two sensors 140(1), 140(2) in FIG. 1A) may be provided. An individual identification number is assigned to each component-side device 110 (110(1) and 110(2) in FIG. 1A), and the corresponding relationship among each component-side device 110, component 132, and sensor 140 is set in advance. back. As a result, the main unit 120 distinguishes and communicates between the component 132 and the sensor 140 corresponding to each component-side device 110, for example, the sensor 140(1) and the component 132(1) corresponding to the component-side device 110(1). be able to.

FIG. 1B is an overall configuration diagram of an electric field communication system 100B according to an embodiment of the present disclosure. Like the electric field communication system 100A shown in FIG. 1A, the electric field communication system 100B is mainly composed of a component side device 110, a main body side device 120, and a communication medium 130 for transmitting an electric field. The electric field communication system 100B of FIG. 1B is different from the electric field communication system 100A shown in FIG. 1A in that the component side device 110 further includes a transmitter 210a and the main body side device 120 includes a receiver 220b. FIG. 1B also illustrates the electric field ef propagating through the communication medium 130 . The electric field ef is transmitted through the part 132 , the connecting portion 134 , and the portion of the main body 136 made of a material capable of transmitting an electric field, such as metal, as the communication medium 130 .

The component-side device 110 includes a transmitter 210a that transmits a signal to the receiver 220b of the main body-side device 120. FIG. The component-side transmitter 210a transmits, for example, an identification signal assigned to each transmitter 210a and an output signal received from the sensor 140 to the receiver 220b. Each transmitter 210a can be uniquely identified by the individual identification number assigned to each transmitter 210a on the component side.

The main device 120 includes a receiver 220b that receives a signal from the transmitter 210a of the component device 110 and is located at a distance from the transmitter 210a. In the case of electric field communication, the receiver 220b may be arranged within the electric field generated by the transmitter 210a.

According to the present disclosure, by placing receiver 220b within the electric field generated by transmitter 210a and bringing receiver 220b and transmitter 210a into contact with communication medium 130, a material capable of transmitting the electric field of the work device, such as a metal, can be used. A communication network or the like is established by using the portion configured as a communication medium 130 . Therefore, it is not necessary to provide wired equipment including cables and wireless equipment including antennas. As a result of eliminating the need for wired equipment, heavy cables are no longer required, for example, it is possible to improve the fuel consumption per working hour of a power shovel. Efficiency can be improved.

Furthermore, according to the present disclosure, by detecting the magnitude of the signal transmitted from the transmitter 210a on the receiver 220b side, attachment/detachment of the component 132 or the like can be performed without separately providing a device for monitoring attachment/detachment of the component 132. state can be detected. As an example, if the magnitude of the signal received by receiver 220b is less than a threshold, it may be determined that component 132 is disconnected from connection 134 .

Returning to FIG. 1B, the sensor 140, the processing unit 150, and the external communication device 160 will be described. The sensor 140 is a sensor that detects various physical quantities that indicate the state of the component 132. For example, a sensor that detects the movement of the component (vibration sensor, speed sensor, acceleration sensor, angular velocity sensor, etc.) (a temperature sensor that measures the temperature of component 132, a humidity sensor that measures the humidity of the environment surrounding component 132), or a combination thereof. When sensor 140 detects the state of component 132 , sensor 140 transmits an output signal indicating this state to component-side device 110 . A plurality of sensors 140 (for example, three sensors of temperature sensor, humidity sensor, and atmospheric pressure sensor) may be arranged in one component 132 . The output signals from these multiple sensors are sent to the component-side device 110 together with the identification number or the like assigned to each sensor 140 . The component-side device 110 transmits the identification number of each sensor and the output signals from the plurality of sensors to the main body-side device 120 via the communication medium 130 .

The processing unit 150 includes a processor (not shown) and a memory (not shown) as main components. In the processing unit 150, the processor appropriately processes the data acquired from the main device 120, and stores the processed data in the memory. The processing unit 150 can also output data stored in the memory to the external communication device 160 and the main device 120 . In this illustrated example, the processing unit 150 is arranged above the main device 120, but is not limited to this, and is communicably connected to the main device 120 and the external communication device 160. It is good if there is

The processing unit 150 can detect whether or not the part 132 has been removed from the connection unit 134 . The processing unit 150 determines that the magnitude of the signal generated by the potential difference generated based on the electric field transmitted from the transmitter 210a of the component-side device 110 received by the receiver 220b of the main-body device 120 is less than a threshold value or substantially zero. , it is determined that the component is detached from the connecting portion 134 .

Furthermore, the processing unit 150 uses the data from the various sensors 140 acquired from the main body device 120 and the identification number assigned to the transmitter 210a on the part side to determine whether each component 132 is connected to the main body 136. status, such as operating hours, can be calculated.

More specifically, the processing unit 150 acquires an identification signal assigned to the transmitter 210a of the component 132 attached to the main body 136, and acquires an output signal from the sensor 140 that detects movement of the component 132. do. The processing unit 150 can integrate the time for which the output signal acquired from the sensor 140 is equal to or greater than the threshold value, and can calculate the operating time of the component 132 with the component 132 attached from the integrated time. As a result, when the operating time exceeds the specified time, the processing unit 150 controls the component 132 by emitting an alarm sound or displaying an alarm prompting maintenance of the component 132 or replacement of the component 132. It is possible to notify workers, etc. who are

In addition, the processing unit 150 determines whether each component 132 is attached to the main body 136 based on an output signal from a sensor 140 (for example, a temperature sensor or a humidity sensor) that detects the surrounding environment of the component 132 and an identification signal from the transmitter 210a. It is possible to grasp the operating environment in the state where Accordingly, the processing unit 150 can determine and monitor whether the component 132 is working in an appropriate operating environment (for example, appropriate temperature and appropriate humidity). If the operating environment for work using the component is not appropriate, the processing unit 150 can notify the worker or the like that the component 132 is not placed in the appropriate operating environment by an alarm sound or display.

The external communication device 160 is a device that transmits the operating status of each component acquired by the processing unit 150 to an external computer (not shown) via a network such as the Internet. The external administrator can collectively manage the operation status of each component 132 based on the information received by the external computer from the external communication device 160 . Therefore, the external manager can place an order for replacement parts or the like at an appropriate timing without going to the site where the working device is operated and periodically inspecting the working device. In this illustrated example, the external communication device 160 is arranged above the processing unit 150, but is not limited to this, and is communicably connected to the processing unit 150 and an external computer (not shown). It is good if there is

According to the present disclosure, based on various physical quantities indicating the state of the component 132 acquired from the sensor 140, the processing unit 150 obtains the operating status of the component and notifies the worker, or the external communication device 160 communicates with the external administrator. can be notified. Therefore, a worker or an external administrator can grasp the operation status of the component 132 while in contact with the main body 136, and can appropriately manage the component 132. FIG. As a result, it is possible to reduce troubles caused by abnormal wear of parts and overloads, thereby enhancing work safety and improving work efficiency.

It should be noted that the combination of the part 132, the connecting portion 134, and the main body 136 can be applied to various types of working devices. The electric field communication system 100B can be used not only for the power excavator (FIG. 1A) described above, but also for other construction machines (bulldozers, crane trucks, road rollers, etc.), cars, trains, robot arms, tools, medical equipment (scalpels, forceps, etc.). ) can also be applied.

For example, when the electric field communication system 100B of the present disclosure is applied to a car, the parts 132 are tire wheels, doors, etc., the connection part 134 is a frame constituting the vehicle body, etc., and the main body 136 is the controller of the vehicle body. In this example, the component 132, the connection portion 134, and the main body 136 are configured separately, but the component 132 and the connection portion 134 may be configured integrally. physical contact with body 136 . For example, if the disclosed electric field communication system 100 is applied to a car, the component 132' may be the car door and the body 136 may be the car controller. Part 132' is provided with a power window switch sensor 140 and a transmitter 210a for transmitting the signal from the sensor 140. FIG. The body 136 is provided with a receiver 220b for receiving the signal of 210a from the transmitter in the controller. As a result, when the sensor 140 detects an instruction to raise or lower the power window, an output signal from the sensor 140 can be transmitted to the controller of the vehicle by electric field communication. Alternatively, the component-side device 110 and the main body-side device 120 may be arranged on a single main body 136 ′ in which the component 132 , the connecting portion 134 and the main body 136 are integrated.

Further, for example, when the electric field communication system 100 of the present disclosure is applied to a robot arm, the part 132 is a tip tool such as a robot hand attached to the tip of the robot arm, the connection part 134 is the robot arm, and the main body 136 is the robot arm. It is a pedestal.

Furthermore, for example, when the electric field communication system 100 of the present disclosure is applied to a power tool, the part 132 is an attachment attached to the tip of the arm of the tool, the connection part 134 is the arm of the tool, and the main body 136 is the main body of the tool. is.

FIG. 1C is an overall configuration diagram of an electric field communication system 100C according to an embodiment of the present disclosure. The electric field communication system 100C has the electric field communication shown in FIG. Differs from system 100B. The description of the configuration already described with reference to FIG. 1B will be omitted below.

The receiver 220 a of the component-side device 110 receives a signal from the transmitter 210 b of the main-body device 120 . The receiver 220a on the component side receives, for example, a signal for controlling the component 132 transmitted from the transmitter 210b, for example, a sensor information transmission request signal for the sensor 140. FIG.

The transmitter 210 b of the main body device 120 transmits a signal to the receiver 220 a of the component device 110 . Note that the electric field communication systems 100B and 100C shown in FIG. 1B and FIG. 1C are examples, and the configuration of the electric field communication system is not limited to this. As an example, the electric field communication system 100 may be composed of a component side device 110 having a receiver 220a and a main body side device 120 having a transmitter 210b.

<First Embodiment>
FIG. 2 is a schematic diagram showing the configuration according to the first embodiment of the electric field communication system 100C (FIG. 1C). Hereinafter, the communication principle of the electric field communication system 200 according to the first embodiment will be schematically described with reference to FIG. The electric field communication system 200 shown in FIG. 2 communicates between the transmitter 210a (FIG. 1C) of the component-side device 110 (FIG. 1C) and the receiver 220b (FIG. 1C) of the main body-side device 120 (FIG. 1C), or This system performs electric field communication via a communication medium 130 for communication between a receiver 220a (FIG. 1C) of a component-side device 110 and a transmitter 210b (FIG. 1C) of a main body-side device 120. FIG. Hereinafter, the transmitter 210a of the component-side device and the transmitter 210b of the main body-side device are collectively referred to as the transmitter 210, and the receiver 220a of the component-side device and the receiver 220b of the main body-side device are simply referred to as the receiver 220. Sometimes.

The transmitter 210 includes a first electrode 212, a second electrode 214 arranged parallel to the first electrode 212, and a transmission circuit 216 for electric field communication connected to each of these electrodes and provided between these electrodes. Mainly composed of The first electrode 212 is connected to the signal side of the transmission circuit 216 and the second electrode 214 is connected to the ground side of the transmission circuit 216 . In the present disclosure, an electrode connected to the signal side of the transmission circuit 216 is called a signal electrode, and an electrode connected to the ground side of the transmission circuit 216 is called a ground electrode. The first electrode 212, the second electrode 214, and the transmission circuit 216 are provided in one housing made of an insulator. A first electrode 212 is disposed on one inner surface within the housing, facing the communication medium 130, and a second electrode 214 is disposed on the other inner surface within the housing. The surface of the second electrode 214 opposite to the surface facing the first electrode 212 faces the space around the transmitter 210 . The first electrode 212 and the second electrode 214 preferably have substantially the same size and shape, each having a planar shape with sufficient area for electric field communication. The first electrode 212 and the second electrode 214 are rectangular, for example.

The receiver 220 includes a third electrode 222, a fourth electrode 224 arranged parallel to the third electrode 222, and a receiving circuit 226 for electric field communication connected to each of these electrodes and provided between these electrodes. Mainly composed of The third electrode 222 is connected to the signal side of the receiving circuit 226 and the fourth electrode 224 is connected to the ground side of the receiving circuit 226 . In the present disclosure, an electrode connected to the signal side of the receiving circuit 226 is called a signal electrode, and an electrode connected to the ground side of the receiving circuit 226 is called a ground electrode. The third electrode 222, the fourth electrode 224, and the receiving circuit 226 are provided in one housing made of an insulator. The third electrode 222 is arranged on one inner surface of the housing on the side of the communication medium 130 . The fourth electrode 224 is arranged on the other inner surface of the housing, and the surface of the fourth electrode 224 opposite to the surface facing the third electrode 222 faces the space around the receiver 220 . The third electrode 222 and the fourth electrode 224 preferably have substantially the same size and shape, each having a planar shape with a sufficient area for electric field communication. The third electrode 222 and the fourth electrode 224 are rectangular, for example.

Transmitter 210 (transmitting circuit 216) modulates an output signal or the like from sensor 140 (FIGS. 1A to 1C) into an electrical signal to be transmitted to receiver 220, and transmits this electrical signal to first electrode 212 and second electrode. It is output as a time-varying voltage across the two electrodes 214 . For example, transmitter 210 may analog-to-digital (A/D) convert signals obtained from sensor 140 (FIG. 1C) and transmit the converted digital signals to first electrode 212 and second electrode 214. It is output as a time-varying voltage (for example, an ASK modulated signal). Then, a potential difference is generated between the first electrode 212 and the second electrode 214 to generate an electric field. This electric field is transmitted to receiver 220 via communication medium 130 . The receiver 220 is placed within the electric field generated by the transmitter 210, and when the generated electric field creates a potential difference between the third electrode 222 and the fourth electrode 224 of the receiver 220, the receiver circuit 226 is detected and demodulated, the data transmitted from the transmitter 210 can be obtained.

Transmitter 210 may include internal power supply 218 for providing power to operate transmitter circuitry 216 therein. The internal power source 218 is, for example, a vibration power generator that generates electric power using energy generated by vibration of the component 132, a solar power generator that generates power using sunlight, or a battery. The battery may be, for example, a battery that is charged by an electric field transmitted from the main body device 120 . According to the electric field communication system 200 of the present disclosure, by transmitting an electric field, instead of transmitting and receiving data between the transmitter 210 and the receiver 220, power is transmitted and received instead of transmitting and receiving data. be able to. As an example, by transmitting power from the transmitter 210b (FIG. 1C) of the main body device 120 to the receiver 220a (FIG. 1C) of the component device 110, the component device 110 does not need a power source such as a battery. Become. Also, if the internal power source of the component-side device 110 is a secondary battery or the like, the secondary battery can be charged by transmitting an electric field. Note that the receiver 220 may also include an internal power supply 228, like the transmitter 210. FIG.

FIG. 3 is a diagram showing a configuration example of the electric field communication system 200 shown in FIG. 2 according to an embodiment of the present disclosure. The electric field communication system 300 shown in FIG. 3 includes a transmitter 210, a receiver 220, and a communication medium 130, like the electric field communication system 200 shown in FIG.

Transmitter 210 comprises a first electrode 212 and a second electrode 214 . The first electrode 212 is coupled with the communication medium 130 through a coupling capacitance, and the second electrode 214 is coupled with the earth ground 302 and the communication medium 130 through a coupling capacitance. C1 is the capacitance between the second electrode 214 and earth ground 302, C2 is the capacitance between the first electrode 212 and the second electrode 214, and C3 is the capacitance between the second electrode 214 and the communication medium 130. The capacitance between, C4 is the capacitance between the first electrode 212 and the communication medium 130 . For example, when a part 132 (FIG. 1C) forming the communication medium 130 is detached from a connecting portion 134 (FIG. 1C) forming the communication medium 130, the electrostatic capacitance C4 becomes small, and the connection between the transmitter 210 and the communication medium 130 is reduced. Weak electrical coupling. Therefore, the electric field between the transmitter 210 and the receiver 220 is difficult or not transmitted.

Receiver 220 comprises a third electrode 222 , a fourth electrode 224 and a receiver circuit 226 . The third electrode 222 is coupled via coupling capacitance with the communication medium 130 in contact with the receiver 220 and the fourth electrode 224 is coupled via coupling capacitance with earth ground 302 and the communication medium 130 . The fourth electrode 224 is also coupled to the battery ground of the receiver circuit 226 and, as a result, is in communication with the communication medium 130 . C5 is the capacitance of the communication medium 130 to earth ground 302, C6 is the capacitance between the fourth electrode 224 and the communication medium 130, C7 is the capacitance between the third electrode 222 and the fourth electrode, C8 is the capacitance between the second electrode 214 and the fourth electrode 224, C9 is the capacitance between the fourth electrode 224 and earth ground 302, and C10 is the capacitance between the third electrode 222 and the communication medium 130. is the capacitance of A third electrode 222 is connected to the signal side of the receiving circuit 226 and a fourth electrode 224 is connected to the ground side of the receiving circuit 226 . The fourth electrode 224 of receiver 220 is capacitively coupled through earth ground 302, and the second electrode 214 of transmitter 210 is capacitively coupled through earth ground 302, earth ground 302 being the return transmission line. Use as

The communication medium 130 is connected to the battery ground of the receiving circuit 226 and can be represented by a lumped constant of resistance R and inductance L.

FIGS. 4A to 4E are graphs illustrating temporal changes in voltage at each point (P1, P2, P3, P4, P5) shown in the electric field communication system 300 shown in FIG. 4A shows the voltage at the first electrode 212 (transmitting signal electrode, P1) of the transmitter 210, and FIG. 4B shows the voltage at the fourth electrode 224 (receiving ground electrode, P2) of the receiver 220 and earth ground 302 4C shows the voltage at the third electrode 222 (receiver signal electrode, P4) of the receiver 220, respectively. FIG. 4D shows both the voltage at P2 and the voltage at P4. FIG. 4E shows the change over time of P5, that is, the voltage of the received signal in the receiving circuit 226, which corresponds to the potential difference between the voltages of P2 and P4 shown in FIG. 4D.

As shown in FIG. 3 , in the electric field communication system 300 , the fourth electrode 224 of the receiving circuit 226 and the communication medium 130 are electrically connected ( 240 ) via the receiving circuit 226 . This reduces the potential difference between the third electrode 222 and the fourth electrode. The potential P2 at the ground electrode (fourth electrode 224) of the receiver 220 shown in FIG. 4B and the potential P4 at the signal electrode (third electrode 222) of the receiver 220 shown in FIG. 4C have the same phase and approximately the same amplitude. become. Therefore, as shown in FIG. 4E, although there is a potential difference between the potential P4 at the receiver signal electrode (third electrode 222) and the potential P2 at the receiver ground electrode (fourth electrode 224), the potential difference is not large. do not have.

<Second embodiment>
FIG. 5 is a schematic diagram showing the configuration according to the second embodiment of the present disclosure. The electric field communication system 500 shown in FIG. 5 is the same as the electric field communication system 200 shown in FIG. 2 except that the configuration of the receiver 220' is different.

The transmitter 210 shown in FIG. 5 is configured in the same manner as the transmitter 210 described with reference to FIG. 2, so description thereof will be omitted here. The receiver 220′ shown in FIG. 5 includes a third electrode 222, a fourth electrode 224 arranged in parallel with the third electrode 222, and an electric field communication electrode connected to each of these electrodes and provided between these electrodes. , and a receiving circuit 226. The third electrode 222 is connected to the signal side of the receiving circuit 226 and the fourth electrode 224 is connected to the ground side of the receiving circuit 226 . The third electrode 222, the fourth electrode 224, and the receiving circuit 226 are provided in one housing made of an insulator. The third electrode 222 is arranged on one inner surface of the housing, and the surface opposite to the surface facing the fourth electrode of the third electrode 222 faces the space around the receiver 220'. The fourth electrode 224 is arranged on the inner surface inside the housing on the side of the communication medium 130 . A fourth electrode 224 is coupled to the battery ground of the receiver circuit 226 and, as a result, is in communication with the communication medium 130 . Alternatively, the fourth electrode 224 may be in direct communication (240) with the communication medium 130 via a conductor (wire, metal screw, etc.).

FIG. 6 is a diagram showing a configuration example of the electric field communication system 500 shown in FIG. 5 according to an embodiment of the present disclosure. Transmitter 210, receiver 220', and communication medium 130 of electric field communication system 600 shown in FIG. 130.

The transmitter 210 shown in FIG. 6 is configured in the same manner as the transmitter 210 already described with reference to FIG. 3, so description thereof will be omitted. The receiver 220 ′ shown in FIG. 6 comprises a third electrode 222 , a fourth electrode 224 and a receiver circuit 226 . The third electrode 222 is connected to the communication medium 130 contacting the receiver 220 and the earth ground 302 via coupling capacitance. The fourth electrode 224 is in electrical continuity with the communication medium 130 . C6' is the capacitance between the third electrode 222 and the communication medium 130, C7 is the capacitance between the third electrode 222 and the fourth electrode, and C8' is the capacitance between the second electrode 214 and the third electrode 222. , C 9 ′ is the capacitance between the third electrode 222 and earth ground 302 . The third electrode 222 of receiver 220 is capacitively coupled through earth ground 302 and the second electrode 214 of transmitter 210 is capacitively coupled through earth ground 302, earth ground 302 being the return transmission line. Use as

One of the features of the electric field communication system 600 in this embodiment is that the fourth electrode 224 is arranged on the communication medium 130 side. By placing the fourth electrode 224 on the communication medium 130 side, the fourth electrode 224 (the ground electrode) and the third electrode 222 (the signal electrode), the amplitude of the signal input to the receiving circuit 226 can be increased.

7A to 7E are graphs illustrating changes in voltage over time at each point (P1, P2, P3, P4, P5) shown in the electric field communication system 600 shown in FIG. 7A is the voltage at the first electrode 212 (transmitter signal electrode, P1) of the transmitter 210; FIG. 7B is the voltage at the fourth electrode 224 (receiver ground electrode, P2) of the receiver 220; 7C shows the voltage at the third electrode 222 (receiver signal electrode, P4) of the receiver 220, respectively. FIG. 7D shows both the voltage at P2 and the voltage at P4. FIG. 4E shows the time variation of the voltage of the received signal at the receiving circuit 226 (P5), which corresponds to the potential difference between the voltage at P2 and the voltage at P4 shown in FIG. 7D.

The voltage at the third electrode 222 (receiver signal electrode, P4) shown in FIG. 7C has a smaller amplitude than the voltage at the third electrode 222 (receiver signal electrode, P4) shown in FIG. 4C. This is because the third electrode 222 is farther from the communication medium 130 in the configuration of FIG. 6 than the configuration shown in FIG. This is because the amplitude of the signal entering (the receiver signal electrode) is reduced. Therefore, as shown in FIG. 7E, the potential difference between the voltage at the receiver ground electrode and the voltage at the receiver signal electrode when the fourth electrode 224 (receiver ground electrode) is conductive to the communication medium 130 is shown in FIG. greater than the potential difference shown. As a result, the signal input to the receiving circuit 226 can be increased.

FIG. 8 is an example of an equivalent circuit of the electric field communication system 600 shown in FIG. Signal source 802 and capacitance C2 in FIG. 8 correspond to transmitter 210 in FIG. The receiver circuit 226 illustrated in FIG. 8 is a single-ended output amplifier, and the fourth electrode 224 is connected to the ground side of the receiver circuit 226 . Note that the receiving circuit 226 may be a differential amplifier.

One of the features of the electric field communication system 800 of the present disclosure is the placement of the fourth electrode 224 on the communication medium 130 side, as described above in the description of FIG. With this configuration, the potential difference between the fourth electrode 224 and the third electrode 222 is increased, and the signal input to the receiving circuit 226 can be increased. The configuration according to the first embodiment and the configuration corresponding to the second embodiment were actually constructed, and the magnitudes of the signals output from the receiver 220 were compared by experiments. The configuration of the experiment will be described below with reference to FIGS. 9 and 10, and the experimental results with reference to FIG.

FIG. 9 schematically illustrates an experimental setup 900 in one embodiment of the present disclosure. Receiver 220 of experimental setup 900 comprises third electrode 222 , fourth electrode 224 , receiver circuit 226 and electrical/optical converter 910 . In this experiment, a spectrum analyzer (SPA) 930 was used to transmit from the transmitter 210 to the receivers 220 and 220' (hereinafter, the receivers 220 and 220' may be collectively referred to as the receiver 220), and received. The signal output from the machine 220 was measured. An electrical/optical converter (E/O) 910 and an optical/electrical converter (O/E) 920 are for preventing high-frequency interference between the receiving circuit 226 and the SPA 930, and are insulating housings. placed in the body.

10A and 10B are cross-sectional views of the experimental setup shown in FIG. 9, respectively. FIG. 10A arranges the third electrode 222 (receiver signal electrode) on the communication medium 130 side and corresponds to the system 300 according to the first embodiment shown in FIG. FIG. 10B corresponds to the system 600 according to the second embodiment shown in FIG. 6, with the fourth electrode 224 (receiver ground electrode) in communication with and on the side of the communication medium 130 . In the experiment, graphs of the output signals at the receivers 220 and 220' were obtained using the spectrum analyzer 930 in each of the configurations of FIGS. 10A and 10B. As a result of analyzing the output signal strength from the graph of the obtained output signal, the output signal strength on the receiver 220 side was −61.17 dBm in the configuration of FIG. 10A and −41.76 dBm in the configuration of FIG. 10B. , the signal level obtained at the receiver side was higher.

FIG. 11 is a schematic illustration of an experimental setup 1100 in accordance with one embodiment of the present disclosure. Transmitter 210 of experimental configuration 1100 comprises first electrode 212 , second electrode 214 and receiver 220 ( 220 ′) comprises third electrode 222 , fourth electrode 224 . In this experiment, a signal line of an oscilloscope 1102 was connected to each electrode (first electrode 212, second electrode 214, third electrode 222, and fourth electrode 224), and the third electrode 222 and the third electrode 222 of the receiver 220 The change over time of the output voltage waveform received at the four electrodes 224 was observed. ,

12A, 12B, and 12C are all simplified diagrams of configurations corresponding to experimental configuration 1100 shown in FIG. 12A and 12B, the third electrode 222 (receiver signal electrode) is arranged on the communication medium 130 side, and corresponds to the system 300 according to the first embodiment shown in FIG. 12B differs from the receiver 220 shown in FIG. 12A in that the fourth electrode 224 (receiver ground electrode) is electrically connected to the communication medium 130 . The configuration of the receiver 220 in FIG. 12B is closer to the actual configuration than the configuration of the receiver 220'' in FIG. 12A. That is, when the configuration of the present disclosure is applied to a power shovel, the battery ground of the receiving circuit 226 and the frame portion of the power shovel, which is the communication medium 130, are electrically connected via the receiving circuit 226, and as a result A fourth electrode 224 conducts with the communication medium 130 . 12C corresponds to the system 600 according to the second embodiment shown in FIG. 6, in which the fourth electrode 224 (receiver ground electrode) is arranged on the side of the communication medium 130 and in communication with the communication medium 130. FIG. .

13A, 13B, and 13C respectively show part of the output signal waveform obtained as a result of simulating the configuration of FIG. 12A, the configuration of FIG. 12B, and the configuration of FIG. 12C. In the graphs shown in FIGS. 13A, 13B, and 13C, dark colors indicate changes over time in the potential at the fourth electrode 224 (receiver ground electrode, P2), and light colors indicate changes at the third electrode 222 (receiver signal electrode, P4). Figure 2 shows the time change in potential.

According to the simulation results, the potential difference between the third electrode 222 and the fourth electrode 224 shown in FIG. 13B is larger than the potential difference between the third electrode 222 and the fourth electrode 224 shown in FIG. 13A. is also small. This is because, in the configuration of FIG. 12B, the fourth electrode 224 is electrically connected to the communication medium 130, so that the voltage at the fourth electrode 224 (ground electrode) increases and the potential difference between the third electrode 222 and the fourth electrode increases. This is because it decreases.

Further, according to the simulation results, the potential difference between the voltage at the third electrode 222 and the voltage at the fourth electrode 224 shown in FIG. 13C is higher than that between the voltage at the third electrode 222 and the voltage at the fourth electrode 224 shown in FIG. bigger than As shown in FIG. 12C, by arranging the fourth electrode 224 on the side of the communication medium and arranging the third electrode 222 away from the side of the communication medium 130, a This is because the capacitive coupling between the third electrode 222 and the fourth electrode 224 is increased as a result of the decrease in the amplitude of the voltage at the third electrode 222 .

According to the present disclosure, by arranging the fourth electrode 224 on the communication medium 130 side as shown in FIG. Also, the potential difference between the potential P2 at the fourth electrode 224 and the potential P4 at the third electrode 222 can be increased, and the communication efficiency between the transmitter 210 and the receiver 220 can be improved.

<Third Embodiment>
FIG. 14 is a diagram illustrating a configuration example of an electric field communication system 1400 according to an embodiment of the present disclosure. Electric field communication system 1400 includes transmitter 210, receiver 220, and communication medium 130 in the same manner as electric field communication system 300 shown in FIG. different. Thus, in FIG. 14, transmitter 210 and receiver 220 are positioned between communication medium 130 and earth ground 302 . The electric field communication system 1400 shown in FIG. 14 has the same equivalent circuit as that of the electric field communication system 300 described with reference to FIG.

As noted above, transmitter 210 and receiver 220 are placed in physical contact between communication medium 130 and earth ground 302 . Therefore, the distance between the second electrode 214 (transmitter ground electrode) and the earth ground 302 is shortened, and the capacitance C1 between the second electrode 214 and the earth ground 302 is increased. Also, the distance between the fourth electrode 224 (receiver ground electrode) and the earth ground 302 is shortened, and the capacitance C9 between the fourth electrode 224 and the earth ground 302 is increased. As the capacitances C1 and C9 increase, the impedances X1 and X9 (not shown) decrease, respectively, and the voltage across these impedances decreases. Due to the law of voltage division, the voltage applied to other capacitances, such as the capacitance C7 between the third electrode 222 and the fourth electrode, becomes relatively high. This results in higher signal strength and improved voltage gain at the receiver 220 side. Hereinafter, as shown in FIGS. 15A to 15D , various positions of the transmitter 210 and the receiver 220 were changed to measure how the signal strength obtained by the receiver 220 changed.

15A-15D are simplified diagrams corresponding to the experimental setup shown in FIG. 9, respectively. 15A-15D show transmitter 210 and receiver 220 placed in physical contact on or between communication medium 130 and earth ground 302, respectively. The configuration shown in FIG. 15A corresponds to the configuration of electric field communication system 300 shown in FIG. 3, and the configuration shown in FIG. 15D corresponds to the configuration of electric field communication system 1400 shown in FIG.

15A, both transmitter 210 and receiver 220 are placed on communication medium 130 in physical contact with communication medium 130. In FIG. More specifically, the first electrode 212 of the transmitter 210 and the third electrode 222 of the receiver 220 are arranged on the communication medium 130 side. In the configuration shown in FIG. 15A, the signal gain obtained at receiver 220 was −106.635 dB.

In FIG. 15B, transmitter 210 is placed in physical contact with communication medium 130 and receiver 220 is placed between communication medium 130 and earth ground 302 . One side of receiver 220 is placed in physical contact with communication medium 130 . More specifically, the first electrode 212 of the transmitter 210 and the third electrode 222 of the receiver 220 are arranged on the communication medium 130 side and connected to the communication medium 130 via capacitive coupling. A fourth electrode 224 of the receiver 220 is arranged on the earth ground 302 side and is connected to the earth ground 302 via capacitive coupling. According to this configuration, the capacitance C9 (FIG. 14) between the fourth electrode 224 and the earth ground 302 is increased. As capacitance C9 increases, impedance X9 (not shown) decreases, lowering the voltage across these impedances. Due to the law of voltage division, the voltage across the capacitance between the third electrode 222 and the fourth electrode relative to the capacitance between the third electrode 222 and the fourth electrode measured in the configuration of FIG. It becomes higher than the voltage applied to the capacitance C7. Therefore, in the configuration shown in Figure 15B, the gain of the signal output from the receiver 220 is -98.3545 dB, which is higher than that obtained in the configuration of Figure 15A.

FIG. 15C shows transmitter 210 placed in physical contact between communication medium 130 and earth ground 302, and receiver 220 in physical contact with communication medium 130 and on communication medium 130. Indicates that it is placed. One side of transmitter 210 is placed in physical contact with communication medium 130 . More specifically, the first electrode 212 of the transmitter 210 is arranged on the communication medium 130 side and connected to the communication medium 130 via capacitive coupling. A second electrode 214 of the transmitter 210 is arranged on the earth ground 302 side and is connected to the earth ground 302 via capacitive coupling. According to this configuration, the voltage across the capacitance C7 between the third electrode 222 and the fourth electrode is equal to the capacitance C7 between the third electrode 222 and the fourth electrode measured in the configuration of FIG. 15A. higher than the voltage applied to Therefore, in the configuration shown in Figure 15C, the gain of the signal output from the receiver 220 is -99.1745 dB, which is higher than that obtained in the configuration of Figure 15A.

FIG. 15D shows both transmitter 210 and receiver 220 placed in contact between communication medium 130 and earth ground 302, respectively. That is, the first electrode 212 of the transmitter 210 and the third electrode 222 of the receiver 220 are arranged on the communication medium 130 side, and the second electrode 214 of the transmitter 210 and the fourth electrode 224 of the receiver 220 are arranged on the earth ground 302 . placed on the side. According to this configuration, the voltage across the capacitance C7 between the third electrode 222 and the fourth electrode is equal to the static voltage between the third electrode 222 and the fourth electrode measured in the configurations of FIGS. 15B and 15C. It becomes higher than the voltage applied to the capacitance C7. Therefore, in the configuration shown in FIG. 15D, the gain of the signal output from receiver 220 is −89.1645 dB, which is higher than the signal gain obtained in the configurations of FIGS. 15B and 15C.

According to the present disclosure, by placing either transmitter 210 or receiver 220 between communication medium 130 and earth ground 302, as shown in FIGS. 15B and 15C, the configuration shown in FIG. also provides high gain at the receiver 220 . Furthermore, as shown in FIG. 15D, by placing both the transmitter 210 and the receiver 220 between the communication medium 130 and the earth ground 302, the receiver 220 has a higher A higher gain is obtained with For example, the measured gain for the configuration shown in FIG. 15A was −106.635 dB, while the gain measured for the configuration shown in FIG. 15D was −89.1645 dB, a difference of about 17.5 dB.

Although the embodiment of the present invention has been described above, the above-described embodiment of the present invention is for facilitating understanding of the present invention, and does not limit the present invention. The present invention may be modified and improved without departing from its spirit, and the present invention includes equivalents thereof. In addition, any combination of the embodiments and modifications is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects, and is described in the scope of claims and the specification. Any combination or omission of each component is possible.

For example, FIG. 16 is a schematic diagram of an electric field communication system 1600 according to one embodiment of the present disclosure. The component-side device 110 includes a receiver 220a' in addition to the transmitter 210a, and the main body-side device 120 includes a transmitter 210b in addition to the receiver 220b'. A transmitter 210a and a receiver 220b' of the electric field communication system 1200 correspond to the transmitter 210 and the receiver 220' described with reference to FIG. 5, respectively, so description thereof will be omitted here.

The main device 120 physically contacts the communication medium 130 . The transmitter 210 b of the main body device 120 includes a fifth electrode 312 , a sixth electrode 314 and a transmission circuit 316 . A fifth electrode 312 (signal electrode) is connected to the signal side of the transmission circuit 316, and a sixth electrode 314 (ground electrode) is connected to the ground side. The transmission circuit 316 includes a fifth electrode 312 (signal electrode) connected to the communication medium via a coupling capacitance, and a sixth electrode 314 (ground electrode) connected to the earth ground 302 and the communication medium 130 via a coupling capacitance. generates an electric field corresponding to the potential difference between

The component-side device 110 physically contacts the communication medium 130 . The receiver 220 a ′ of the component-side device 110 includes a seventh electrode 322 , an eighth electrode 324 and a receiver circuit 326 . A seventh electrode 322 (signal electrode) is connected to the signal side of the receiving circuit 326, and an eighth electrode 324 (ground electrode) is connected to the ground side. The receiving circuit 326 detects the potential difference generated between the seventh electrode connected to the communication medium 130 and the earth ground 302 via a coupling capacitance and the eighth electrode electrically connected to the communication medium 130, and transmits the potential difference. Get the data sent from the machine. The transmitter 210b of the main device 120 and the receiver 220a' of the component device 110 perform electric field communication via the communication medium 130. FIG.

ef... Electric field 100A, 100B, 100C, 200, 300, 500, 600, 1200... Electric field communication system 110... Component side device 120... Main body side device 130... Communication medium 132... Component 134... Connector 136... Main body 140... Sensor 150 ... processing unit 160 ... external communication device 210 ... transmitter 212 ... first electrode (transmitter signal electrode)
214...Second electrode (transmitter ground electrode)
216... Transmission circuit 220, 220', 220''... Receiver 222... Third electrode (receiver signal electrode)
224... Fourth electrode (receiver ground electrode)
226 -- Receiving circuit 240 -- Continuity

Claims (7)

An electric field communication system that performs communication using an electric field,
a communication medium made of a substance capable of transmitting an electric field, the communication medium comprising a part and a main body;
An electric field is generated according to the potential difference between a first electrode arranged on the communication medium side and connected to the communication medium via a coupling capacitance and a second electrode connected to the earth ground via a coupling capacitance. wherein the first electrode is connected to the signal side of the transmitter and the second electrode is connected to the ground side of the transmitter, the first transmitter being in contact with the component ; ,
a first receiver in contact with the body ;
a processing unit that detects that the component is detached from the main body when the magnitude of a signal generated based on the electric field transmitted from the first transmitter is less than a threshold;
and wherein the first transmitter and the first receiver perform electric field communication via the communication medium. 2. The electric field communication system according to claim 1 , wherein said first receiver comprises:
a third electrode connected to the earth ground via a coupling capacitance;
a fourth electrode disposed on the communication medium side;
a receiving circuit, wherein the third electrode is connected to a signal side of the receiving circuit, and the fourth electrode is connected to a ground side of the receiving circuit; the receiving circuit is connected to the transmitter; An electric field communication system that outputs a signal corresponding to the potential difference between the third electrode and the fourth electrode caused by the electric field transmitted from. 2. The electric field communication system of claim 1 , wherein said first receiver is disposed in contact between said earth ground and said communication medium, said first receiver comprising:
a third electrode disposed on the communication medium side and connected to the communication medium via capacitive coupling;
and a fourth electrode arranged on the earth ground side and connected to the earth ground via capacitive coupling. 4. The electric field communication system according to claim 1 or claim 3 , wherein the first transmitter is arranged in contact between an earth ground and the communication medium,
The electric field communication system, wherein the second electrode of the first transmitter is arranged on the earth ground side. 5. The electric field communication system according to any one of claims 2 to 4 , further comprising detecting the state of the part of the communication medium with which the first transmitter is in contact or the surrounding environment of the part. equipped with a sensor,
The electric field communication system, wherein the first transmitter outputs a signal corresponding to the output signal from the sensor as a time-varying voltage between the first electrode and the second electrode. The electric field communication system according to claim 5 ,
The sensor is a sensor that detects movement of the component,
The electric field communication system, wherein the processing unit further calculates the operating time of the component based on the movement of the component detected by the sensor. The electric field communication system according to claim 5 ,
The sensor is a sensor that detects the surrounding environment of the component ,
The electric field communication system, wherein the processing unit further detects whether the component is placed in an appropriate operating environment based on the surrounding environment of the component detected by the sensor.

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